Ligature joint and seal therefor



Aug. 3, 1965 H. T. MARTIN ETAL LIGATURE JOINT AND SEAL THEREFOR 3 Sheets-Sheet l Filed June 4, 1962 M 1 M 1 w n W n n n l n W M 0 Z a Wj W w j I l M,

Aug. 3, 1965 H. T. MARTIN ETAL 3,197,831

LIGATURE JOINT AND SEAL THEREFOR Filed June 4, 1962 s sheets-sheet 2 ZIN Aug' 3, 1965 H. T. MARTIN ETAL 3,197,831

LIGATURE JOINT AND SEAL THEREFOR Filed June 4, 1962 3 Sheeis-Sheet 3 L S i; r S V I y :mf NU Il' i?, l x

2y 1g l? lmd figg 30 ZZ@ United States Patent C 3,197,831 LIGATURE JOINT AND SEAL THEREFR Hollinshead 'I'. Martin, Evanston, Arvid L. Ericsson, Wheeling, and Ilmar J. Vilcins, Oak Park, lll., assignors to Signode Corporation, a corporation of Delaware Filed June 4, 1962,`Ser. No. 199,847 13 Claims. (Cl. 24--16) is concerned is referred to herein as plastic As used,

plastic refers to materials, natural or synthetic, which may be formed into an `elongated ligature, which are readily deformable under pressures of the same order of magnitude as those ordinarily employed in sealing or forming joints in steel strapping, which are relatively soft compared to steel, which have good elastic and resilience properties, and which tend to conform to the shape of objects forced thereagainst, at room or normal atmospheric temperatures.

-It has been found that in certain situations the elasticity or stretchability of the steel now used in strapping is less than that desired. This diiiculty is particularly apparent where the package is a compressible or expansible one which may have a tendency to swell or cause the strap to be subject to substantial shock loads. Swelling packages may burst straps that are not sufficiently stretchable or elastic, or create serious distortion in the package if the strap is too strong. These and other related problems such as the problem of disposing of removed or scrap strap have brought about a desire for the use of plastic strap. If the plastic strap is of a combustible material such as a nylon, it will be most easily disposed of in an incinerator.

Plastic materials were not effectively held when overlapping portions were secured together with known forms of seals used for steel strap. This was due to several features including those such as the slipperiness of the plastic` and the transverse reduction in the dimensions thereof when the strap was subjected to substantial tensile forces. These problems were further multiplied when it was found that plastic strap had a tendency for cuts or tears therein to run until the strap shredded or separated.

In accordance with the present invention, most of these problems` have been overcome and there is provided a new seal arrangement and joint arrangement which is highly effective with plastic strap to grip and hold the strap. In general, embodiments of this invention provide for gripping distortion of the strap by deformation by the strap engaging surface of the seal and the provision of a seal which is substantially harder than the strap.

There are illustrated in the accompanying drawings and described hereinbelow in this specification several illustra- `tive embodiments of the invention. In each of these, a

seal of steel or other material harder than the plastic strap 3,197,831 Patented Aug. 3, 1965 character of the seal rather than the seal surfaces being smoothed or flattened out. Second, since a strap in tension has a tendency to open the seal and pull the folded or bent parts or sections apart the character of the seal will result in the strap biting into the seal and thereby reduce the tendency of the seal to open and release the strap.

It should be understood, of course, that the foregoing statements as to the reasons for the advantages of a harder seal over a softer seal should not be considered as placing any limitations on the scope or substance of the invention. It has been found that a` seal which is substantially harder than the plastic strap deforms the strap within the seal and provides an effective joint.

It has been found also, in accordance with this invention, that in order to effect a secure joint between the seal and the overlapping portions of the strap, that the irregular strap contacting surfaces of the seal should be such that they do not create a condition in the strap which would cause the strap to tear or shred;

The irregular configurations or character of the strap contacting surfaces of the seal may be provided in a number of different ways. The important aspect, however, is that they create a positive deformation of the strap without tearing the strap. This may be inthe form of metallic weldments or punch press die deformations. In

the latter category, the deformations may appear as serrations, knurls, teeth, wire mesh, drawn burrs or complementary rises and recesses `or rises and apertures in or on the contacting surfaces. j

There are several illustrative embodiments of the present invention shown in the accompanying drawings in which like reference numerals refer to like parts, in which each and every detail shown is included as a part of this specication, and in which:

FIGURE l is an elevational view of a plastic strap and seal joint embodying this invention; I

FIGURES 2, 3 and 4 are illustrative planned views of the interior, strap engaging surfaces of seal blanks showing various surface deformations;

FIGURE 5 is a plan view of a seal blank having transversely arranged bar deformations on the strap contacting surfaces thereof;

FIGURE 6 is a transverse sectionaly view of the seal of FIGURE 5 taken substantially along the line 6-6 of FIGURE 5; t

FIGURE 7 is a transverse sectional view of the seal of FIGURES 5 and 6;

FIGURE 8 is a fragmental longitudinal sectional view of the joint of FIGURE 7 taken substantially along the line 8-8 of FIGURE 7; k

FIGURE 9 is a plan View of a seal blank having strap deforming and gripping ears or tabs formed therein;

FIGURE 10 is an end View of the seal of FIGURE'9 with the tabs or ears bent outwardly to receive overlapped plastic strap portions;

FIGURE 1l is a bottom plan View of a joint formed with the seal of FIGURES 9 and l0;

FIGURE 12 is a plan view of a seal blank having complementary recesses andprojections formed in the body and ange portions thereof;

FIGURE 13 is an end view of the seal of FIGURE 12 with the flanges bent downwardly to receive strap therebetween;

FIGURE 14 is a plan view of a joint formed with the seal of FIGURES 12 and 13;

FIGURE l5 is a transverse sectional view of the joint of FIGURE 14 taken substantially along the line 15-15 of FIGURE 14;

FIGURE 16 is a plan view of the joint of FIGURE 18;

FIGURE 17 is a side elevational view of the joint of FIGURE 16; i

` FIGURE 18 is a transverse sectional view of a partially formed joint wherein projections formed in the iianges are arranged for distortion of the strap into apertures formed complementary therewith in the back or body of the strap;

FIGURE 19 is a fragmental plan view of the interior surface of a seal blank having wire mesh secured to such surface;

FIGURE 20 is a fragmental sectional view of the seal of FIGURE 19;

FIGURE 2l is also a plan view of the interior surface of a seal blank provided with punched or die formed teeth thereon;

FIGURE 22 is a fragmental sectional view taken substantially along the line 22-22 of FIGURE 21;

FIGURE 23 is a fragmental sectional view taken substantially along the line 23-23 of FIGURE 22;

FIGURE 24 is a fragmental plan View of a seal having teeth punched therein;

FIGURE 25 is a fragmental sectional View similar to FIGURE 23, but taken substantially along the line 25-25 of FIGURE 24;

FIGURE 26 is a longitudinal sectional view of a joint formed with the seal of FIGURE 21;

FIGURE 27 isa plan view of a joint having a seal similar to the seal of FIGURE 21, but with the teeth therein alternately arranged;

411 and 12 are formed on the contacting or engaging surfaces of the seal 13. The bars 11 formed on the inner face of the seal back or body are longitudinally spaced and alternately arranged or staggered with respect to the fragmental bars on the inner faces of the flange portions of the seal. These bars may be formed by punching or by welding separate parts onto the seal as desired.

A joint formed with the seal 13 closed about overlapped strap ends 2 and 3 is shown in transverse section in FIGURE 7 and longitudinal section in FIGURE 8.

There it will be seen that the bars form a complementary strap biting and gripping arrangement which'also serves to undulate the strap whereby tensile forces on the strap tend to cause the Istrap toV bite more tightly on the teeth.

' fingers 19. The lingers 19 of the seal blank are bent FIGURE 28 is a fragmental plan View of a seal blank v outwardly from the inner face of the seal to provide a receiving space for the overlapped strap end portions of plastic strap. When the strap end-s are received between the fingers 19, the fingers 19 are then bent back to a position close t-o their original position whereby the strap is wound about the fingers and the transversely extendingk crossbars as shown in FIGURE 11. This causes undulation of the strap and by proper proportion- .K ing of the seal segments, the fingers and crossbars bite number of illustrative embodiments of this invention having in common numerous features of the invention including, without any attempt to list all such features nor place any limitation on the scope of the invention, seal formations which in the completion of a joint of a seal with plastic strapping provide for positive gripping and deformation of the plastic strap as by biting into the strap.

The strap engaging surfaces of the seal are contigurated to grip the strap. Also, the seals are formed of a harder material than the plastic strap so that when the seal is closed and the joint is formed with the seal dis posed about the overlapping portions of the strap, the irregular surface construction will not be flattened or smooth, but will bite into the plastic strap and positively grip and hold the same.

Tests conducted with various embodiments of this invention'have shown that the Vjoints formed have high eiciencies wherein the joint strength approaches the tensile strength of the plastic strap. Tests conducted utilizing plastic strap and ordinary steelseals and crimping techniques demonstrated extremely low efficiencies. In the embodiment of FIGURE 1, the overlapping portions 2 and 3 of the strap secured in the joint construction indicated generally at 1 are firmlyrsecured together by a seal 13.

The interior surfaces or strap contacting surfaces of the seal have irregular formations thereon. The configuration of the formations on the interior face of the seal may take any form which will be effective to bite into the strap. Three of such forms are in FIGURES 2, 3 and 4 which show, respectively, alternate square-faced,V racklike teeth 7 arranged for an inter-'fitting `or complementary deformation and biting of the strap, full fwidth serration 8 and crossed Serrat-ion 9 of a kuur-led configuration.

Another toothed seal and joint arrangement is shown in FIGURES 5-8 in which transversely arranged bars into the upper and lower strapY end portions.

The seal arrangements -of FIGURESlZflS also provide for undulating the strap within thev seal and are equipped with tooth or barlike portions which are effective to grip the strap portions to provide a secure joint construction. In the particular arrangement of FIG- URES 12-15 deep, barlike and cavitylike deformations are provided in the seal. The seal blank 20 is shown in FIGURE 12 with deep, barlike deformations 21 formed in the back or body portion of the seal and projecting inwardly thereof. These deformations extend substantially fully transversely of the back portion. Half length receiving, transversely extending recesses 22 complementary with the barlike deformations 21 are formed in the flange portions 23 of the seal. The deformations including both the bar portions 21 and the recess portions 22 have a depth in this arrangement greater than the thickness of the seal material, although lesser depths may be employed.

The complementary configurations of these deformations provide for effective gripping and undulation holding of the strap ends 2 and 3 as :shown in the joint drawings of FIGURES 14 and 15.

The joint and seal of FIGURES 16-18 are similar to many of the above described joints and seals wherein bar deformations were formed complementary to recesses or apertures. In this arrangement, barlike deformations 23 similar to the recessed deformations 22 in the arrangement of FIGURES 12-15 are formed in the flange portions 24 of the seal 25. These barlike deformations are arranged to extend transversely of the flanges and are disposed in complementary spacing with transversely extending slots 26 in the back or body portion of the seal 25. When the seal is closed and squeezed about the overlapped strap portions 2 and 3, the barlike portions 23 undulate the strap and squeeze the same into the slots 26 to cause undulated configuration of the strap in the joint and positive gripping of theV strap on the faces of the crossbars 27 which remain in the back or body portion of the seal when the slots 26 are cut therein.

FIGURES 19 and 20 illustrate a surface distortion form of strapseal 28 which employs a wireV mesh 29 secured as by welding or soldering to the inner or strap contacting faces of the. seal. .The effect of 'the Wire mesh is similar to theeifect ofthe knurls 9 in the seal of FIGURE ,4 and the serrations or teeth of `seals `such vas those shown in FIGURESAand 3to bite into the strap and securely grip thesame when the seal is squeezed about the strap. i

The seals and joints illustrated in FIGURES 2li-30 use a plurality of relatively small individual teeth to grip the straps disposed within the seals and about which the seals are squeezed; These teeth may take any one of a number of different forms and have a Wide variety of configurations. The significant aspects of the teeth of the seals in these arrangements are that they present a liat face in a direction opposite to the direction of the tensile force in the strap. This provides a greater gripping and biting effect and tends to reduce the effectiveness of forces which tend to -open the seal to release the strap from the seal. The various teeth-v are formed integrally with the seal and are arranged to minimize any tendency to create or permit tearing or shredding of the strap.

The seal of FIGURES 21, 22, and 23 utilizes pyramid or triangularly shaped teeth 30. These teeth are formed in the seal 31 by being partially punched inwardlyifrom the outer surface of the seal in such a manner that the teeth remain integral with the seal. It is clearly seen in FIGURES 22 and 23 that the projecting faces 32 of the teeth formed in the back or body portion of the seal are at and all face in a direction opposite to the tensile direction-of the upper or outer strap 2 asA seen in FIG- URE 26. The teeth 33 in the flange portions 34 of the seal have flat faces 35 which face in the opposite direction from the faces 32 on the teeth 30 so that they are arranged to bite into the lower or inner strap 3 and face in the opposite direction to the tensile force on that strap portion under weld conditions.

The seal 36 of FIGURES 24 and 25 is quite similar to the seal of FIGURES 21-23 and 26, except that the ,teeth 37 thereof are substantially semi-circular in plan View and are more or less coniigurated to resemble the teeth of a rasp. These teeth 37 and the complementary, oppositely facing teeth 38 on the flange portions of the seal 36 are integral with the material of the seal and arranged to face in opposite directions to the directions of the tensile forces to which the straps will be subjected.

The arrangement of FIGURE 27 is also similar to the arrangement of FIGURES` 21-23 and 26, except that the teeth are generally alternately arranged so that adjacent or nearly adjacent teeth face in opposite directions. The seal 39 of FIGURE 27 with its oppositely arranged adjacent teeth 40 is a bi-directi-on seal. That is, it may be placed on the overlapped strap portions in either direction and will form an effective seal or joint with the plastic strap.

The seal of FIGURES 28 and 29 is also similar to the seals of FIGURE 2l, et seq., hereinafter described, but in this arrangement, the integral teeth 41 in the seal 42 are relatively broad, Hat-faced chisel-like teeth, rather than semi-circular, or pyramid, or diamond shaped. AS in the arrangement of FIGURE 2l,v the teeth 41 of the seal 42 of FIGURES 28 and 29 present at'faces in the direction opposite to the direction of the tensile force on the strap which are gripped by the teeth. j

The joint construction of FIGURE 30 is essentially the same as the joint formed by the seal 42 of FIGURES 28 and 29, except that the teeth 43 therein 4are formed by a punch device 44 during or after compression of the seal 45 and the seal 45 may be provided with receiving, strap locking apertures 46 under the area wherein the teeth 43 are to be punched.

The features, structural configurations and arrangements of the various strap, joint and seal arrangements described hereinabove are, generally speaking, interchangeable and widely variable within the scope of the concepts and principles of this invention. Examples `of 6 such variationsare numerous, vbut it should be appreci- `ated that the invention should not be limited to the specific arrangements shown. Tooth bars as well asdeep segmented serrations may be used with recesses and slots as well as various other` deformation coniigurations all within the scope of this invention, so long as there is a strong biting of the surfaceirregularity into the plastic strap andthe seal andl deformation portions thereof are of greater hardness than the strap to effect such biting and deformation of the strap.

We cla-im: i

1. A seal for joining and securing a pair of overlapping straps of plastic material which comprises: a body of sheet material having a hardness which exceeds theV hardness of the plastic strap to be securedthereby, said body including a center wall and a pair of flange walls located on the same -side of said center wall, said center `wall and said iiange walls being interconnected by a pair of longitudinallyextending substantially parallel bends, said center wall having an` irregular formation provided by said body on its strap contacting surface and both of said ange walls having irregular formations on their strap contacting surfaces, said formations on said strap contacting surfaces of said body being of a depth and hardness effective to deform and securely grip `the plastic strap when the seal is closed thereabout and pressed into firm engagement therewith.

2. A seal for joining and securing a pair of overlapping straps of plastic material, as set forth in claim 1 in which said irregular forma-tions are provided by projections integral with and extending inwardly from the ligature contacting surfaces of the seal.

3. A seal for joining and securing a pair of overlapping straps of plastic material, as set forth in claim 2 in which said projections are disposed in complementary relationship so that ligature portions secured thereby are distortedto a corrugated'coniiguration within said seal when said seal is closed thereabout and pressed into firm engagement therewith.

4. A seal for joining and securing a pair of overlapping straps of plastic material, as set forth in claim 2 in which said projections are formed by complementary arranged transversely extending barlike members.

S. A seal for joining and securing a pair of overlapping straps of plastic material, as set forth in claim 2 in which said projections are formed of bar like portions arranged complementary With transversely extending slots in said body.

6. A seal for joining and securing a pair of overlapping straps of plastic material, as set forth in claim 1 in which said irregular formations are provided by transversely extending serrations formed in the ligature contacting surfaces of the seal. j

7. A seal for joining and securing a pair of overlapping straps of plastic material, as set forth in claim 1 in which said irregular formations are provided by displacement of portions of the material of the seal on the ligature contacting surfaces thereof to provide projections extending inwardly from said surfaces.

8. A seal for joining and securing a pair of overlapping straps of plastic material, as set forth in claim 1 in which said irregular formations are formed by elongated projecting burrs formed adjacent apertures in said body and extending inwardly from the ligature contacting faces thereof.

9. A seal for joining and securing a pair of overlapping straps of plastic material, as set forth in claim 8 in which said body has additional apertures therein disposed complementary with the burrs to receive the burrs and plastic material displaced thereby when the seal is closed about the strap and pressed into firm engagement therewith.

10. A seal for joining and securing a pair of overlapping straps of plastic material, as set forth in claim 1 in which said irregular formations are provided by project- 7 ingV elements secured tothe ligature contacting surfaces of theseal. Y

11. A seal for joining and securing a pair of overlapping straps of plastic material, as set forth in claim 1 in which said irregular formationsV are provided by teeth elements projecting inwardly from the ligature contacting surfaces of the seal andformed integrally therewith.

12. A seal for joining and securing a pair of verlap ping straps.- of plastic materials, as' set forth in claim 8 in which said teeth have substantially flat faces at least some of which face in a direction opposite to the direction Vin which ligature secured thereby is tensioned.k

13. A seal for joining. and securing a pair of overlaplaping straps of plastic material, as set forth in claim 6,

in which said serrations extendy across the entire width 732,270 6703 Bowman.v 1,173,998 2/16= Depew 24-23 '7/17 Fork 24-2l 11/18` Brooks 24-21 2/42 Cooper 24-23 4/48 Anderson 24-135 9/49 Anderson 24-135 11/51 Matthysse.

6/54 Radtke, 24-*16 8/55 Ustin 339-276 1/58 Beaudry 132-48 4/ 62 Karass 24-16 X 7/62 Wade 24-18 FOREIGN PATENTS 3/27 Germany;

DONLEY I. STOCKING, Prz'may'Examz'ner.

SAMUEL KOREN, M. HENSON WOOD, JR.,

- Examiners. 

1. A SEAL FOR JOINING AND SECURING A PAIR OF OVERLAPPING STRAPS OF PLASTIC MATERIAL WHICH COMPRISES: A BODY OF SHEET MATERIAL HAVING A HARDNESS WHICH EXCEEDS THE HARDNESS OF THE PLASTIC STRAP TO BE SECURED THEREBY, SAID BODY INCLUDING A CENTER WALL AND A PAIR OF FLANGE WALLS LOCATED ON THE SAME SIDE OF SAID CENTER WALL, SAID CENTER WALL AND SAID FLANGE WALLS BEING INTERCONNECTED BY A PAIR OF LONGITUDINALLY EXTENDING SUBSTANTIALLY PARALLEL BENDS, SAID CENTER WALL HAVING AN IRREGULAR FORMATION PROVIDED BY SAID BODY ON ITS STRAP CONTACTING SURFACE AND BOTH OF SAID FLANGE WALLS HAVING IRREGULAR FORMATIONS ON THEIR STRAP CONTACTING SURFACES, SAID FORMATIONS ON SAID STRAP CONTACTING SURFACES OF SAID BODY BEING OF A DEPTH AND HARDNESS EFFECTIVE TO DEFORM AND SECURELY GRIP THE PLASTIC STRAP WHEN THE SEAL IS CLOSED THEREABOUT AND PRESSED INTO FIRM ENGAGEMENT THEREWITH. 